[edk2-devel] [PATCH v4 17/28] OvmfPkg: Use GetMemoryProtectionsLib instead of Memory Protection PCDs

[Taylor Beebe]

Replace references to the memory protection PCDs to instead
check the platform protections via GetMemoryProtectionsLib.

Because the protection profile is equivalent to the PCD settings,
this updated does not cause a torn state.

Signed-off-by: Taylor Beebe <taylor.d.be...@gmail.com>
Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org>
Cc: Jiewen Yao <jiewen....@intel.com>
Cc: Jordan Justen <jordan.l.jus...@intel.com>
Cc: Gerd Hoffmann <kra...@redhat.com>
Cc: Leif Lindholm <quic_llind...@quicinc.com>
Cc: Abner Chang <abner.ch...@amd.com>
---
 OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c   | 5 ++---
 OvmfPkg/QemuVideoDxe/VbeShim.c        | 3 ++-
 OvmfPkg/Fdt/HighMemDxe/HighMemDxe.inf | 4 +---
 OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf | 2 +-
 4 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c 
b/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c
index 779bf5c827f5..2bef34427341 100644
--- a/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c
+++ b/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c
@@ -13,6 +13,7 @@
 #include <Library/DxeServicesTableLib.h>
 #include <Library/PcdLib.h>
 #include <Library/UefiBootServicesTableLib.h>
+#include <Library/GetMemoryProtectionsLib.h>
 
 #include <Protocol/Cpu.h>
 #include <Protocol/FdtClient.h>
@@ -148,9 +149,7 @@ InitializeHighMemDxe (
         // on the page table mappings by going through the cpu arch protocol.
         //
         Attributes = EFI_MEMORY_WB;
-        if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) &
-             (1U << (UINT32)EfiConventionalMemory)) != 0)
-        {
+        if 
(gMps.Dxe.ExecutionProtection.EnabledForType[EfiConventionalMemory]) {
           Attributes |= EFI_MEMORY_XP;
         }
 
diff --git a/OvmfPkg/QemuVideoDxe/VbeShim.c b/OvmfPkg/QemuVideoDxe/VbeShim.c
index 8f151b96f9a5..a60e409f50de 100644
--- a/OvmfPkg/QemuVideoDxe/VbeShim.c
+++ b/OvmfPkg/QemuVideoDxe/VbeShim.c
@@ -19,6 +19,7 @@
 #include <Library/DebugLib.h>
 #include <Library/PciLib.h>
 #include <Library/PrintLib.h>
+#include <Library/GetMemoryProtectionsLib.h>
 #include <OvmfPlatforms.h>
 
 #include "Qemu.h"
@@ -69,7 +70,7 @@ InstallVbeShim (
   UINTN                 Printed;
   VBE_MODE_INFO         *VbeModeInfo;
 
-  if ((PcdGet8 (PcdNullPointerDetectionPropertyMask) & (BIT0|BIT7)) == BIT0) {
+  if (gMps.Dxe.NullPointerDetection.Enabled && 
!gMps.Dxe.NullPointerDetection.DisableEndOfDxe) {
     DEBUG ((
       DEBUG_WARN,
       "%a: page 0 protected, not installing VBE shim\n",
diff --git a/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.inf 
b/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.inf
index c7dde9f455f2..40cbbe1c39af 100644
--- a/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.inf
+++ b/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.inf
@@ -33,13 +33,11 @@ [LibraryClasses]
   PcdLib
   UefiBootServicesTableLib
   UefiDriverEntryPoint
+  GetMemoryProtectionsLib
 
 [Protocols]
   gEfiCpuArchProtocolGuid                 ## CONSUMES
   gFdtClientProtocolGuid                  ## CONSUMES
 
-[Pcd]
-  gEfiMdeModulePkgTokenSpaceGuid.PcdDxeNxMemoryProtectionPolicy
-
 [Depex]
   gEfiCpuArchProtocolGuid AND gFdtClientProtocolGuid
diff --git a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf 
b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
index 43a6e07faa88..15693ce85674 100644
--- a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+++ b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
@@ -55,6 +55,7 @@ [LibraryClasses]
   UefiBootServicesTableLib
   UefiDriverEntryPoint
   UefiLib
+  GetMemoryProtectionsLib
 
 [Protocols]
   gEfiGraphicsOutputProtocolGuid                # PROTOCOL BY_START
@@ -64,6 +65,5 @@ [Protocols]
 [Pcd]
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId
   gUefiOvmfPkgTokenSpaceGuid.PcdVideoResolutionSource
-  gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask
   gEfiMdeModulePkgTokenSpaceGuid.PcdVideoHorizontalResolution
   gEfiMdeModulePkgTokenSpaceGuid.PcdVideoVerticalResolution
-- 
2.42.0.windows.2



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